hello, i have a stock-rebuilt super /6. carter bbd 2 bbl. i was thinking of what 4 bbl carb will work after a few mild mods, was thinking of head work-mild gasket match and shave .030 off. also maybe a hotter cam. what 4 bbl will be good, ive heard a holley 390 is a good carb with mild mods,,, thanks,,,,,,,,,,,,,,,,,,, alf44

You can run quite the build before you need a 4 barrel....

Do all your engine mods first....get it running with the BBD.....then look at manifold changes.

I would spend money on a 2.25" exhaust and good muffler before getting a 4 barrel.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

There are a lot of folks that have built for 4bbl's. It's important to make your compression adjustments based on chamber volume. CC the head first, then determine how much needs to be taken off to hit your compression goal. Cutting 0.xx off the head can't be answered until you know where your starting from. Chamber sizes vary widely.

In many cases, mild builds won't benefit from a 4bbl as much as you might think, if at all.

The 390 will be a good choice for less radical builds. I ran a 390 for quite a while. There is some tuning work ahead, so be ready for that. Ignition timing and curve, compression, cam choice, and further flow work - to include exhaust upgrade choices need to be considered up front.

Other popular carburetors are the Edelbrock and Carter 500 and 600 offerings, as they are commonly available.

More radical builds use Two barrel 350 and 500 cfm Holley's, 600 cfm Holley 4 bbls, and periodically you will see all out race motors with 600 cfm double pumpers.

I currently run a 500 cfm Carter AFB. The AVS is another consideration for ease of adjustment.

To effectively use the 390, you will want higher than 8:1 compression. 9 or 9.5:1 is commonly the target.

I run 10.3:1 to good effect. I'm just beyond the point where the engine will burn Regular Unleaded. It's not a Daily Driver, so I don't sweat it.

To determine specifics on how you should proceed, further information is needed about your goals and how your car is set up. Torque converter stall, rear gears, and use would be helpful.

There are a lot of builds out there, some don't cost much, others are a wee bit pricey. Budget is going to be an important part of your equation.
If you don't want to spend five grand on the build, a Stroker would be a poor choice unless you have your own machine shop and jobber parts rates!

CJ

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Part of Tyrde-Browne Racing

I agree with sandy,and ceej,you can have a very warm S/6 and not need a 4BBL carb.I tried a holley 390cfm on a 9.5 CR 0.470 lift cam,ported head engine that I was running.I also had 3.55 gears and a 2,800 stall torque converter.The carb seems to be too big,and the ONLY reason I am sticking with it is I need the solid cork floats to use a blow-through turbo set-up.I beleive aggressive ted was doing well with an engine similar to mine with the stock 1BBL.

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V8?? We don't need no stink'n V8!!

I'm interested in the 4 bbl as well. The 390 uses screw in jets in the primaries and a metering plate for the secondaries. I queried Summit about a plate with the jetting recommended by the Mopar Six Cylinder book. They said that Holley no longer stocks the plates under the part number I had (134-7 or 134-34).

The option at this point is to use an adapter plate such as the AED Holley 6320 4160 Adjustable Metering Plate. As I understand it, this uses conventional Holley jets and therefore allows tuning on the carburetor. Do I understand correctly? Does anyone have experience with this kind of plate? Opinions, criticisms, derrogatory remarks?

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You can't fix stupid. - Ron White

Holley 34-6 or 34-13 kits convert to a jetted metering block.

Add an "S" behind the part number to get the plated metering blocks.
The -6 is side hung floats, the -13 is for the center hung floats.

No more plates.

CJ

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Part of Tyrde-Browne Racing

Make sure when you install the 4 bbl that the primaries are facing the engine. Don't mount it inline with the engine like one would on a V8.
Check out the old Mopar Tech manual at http://flag.blackened.net/mopar/carbs.html

I have a Holley 390 on a 225 with a ported head, 8.5:1 CR, stock cam and long block. Offy manifold primaries toward the driver's side. Works pretty darn good.

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Joshua

That diagram shows it set up on a hyperpak with the primarys to the engine, it also says to use a 600 double pumper withe the primarys to the front of the car. I say just run it where it runs best, i run my 4bbl with the primarys to the fender(drivers side) of the car and all my plugs look the same and the hook up of the throttle cable and kick down were not a pain to hook up.
Just my 2c..

TF

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Even in moderation i am excessive!

I run my Eddy 14XX carbs with the primarys to the engine side as well. Works Great. I like the Eddy because they work Great right out of the box.
Frank

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Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

I run a Holley 390 with Clifford intake & shorty headers with twin pipes to the bump’ah, and an undignified spec. cam ( most likely an Erson E470621 as it starts to make torque above 2000 rpm. & has a real loppy idle under 1000 rpm.), and a 3.55:1 Suregrip. Head is ported, gasket matched, and shaved to produce 9.5:1 compression, bore is +0.030 with stock crank.

Yes, I CC’ed the head, measured how far down the pistons sat at TDC, and than used an online compression calculator to calculate what needed to be done before any machine work was performed. This combination caused low vacuum readings at in gear idle (8-9 in. Hg), and 16-17 at 3000 rpm) due to the cam.

Due to poor low end drivability, I had to re-curve the distributor, tune the carburetor, and install a 2600 rpm (V8 rating = about 2100 rpm) torque converter so the car would sit still at a stoplight while in gear, and get off the line smartly. Presently the engine pulls strongly between 3000 & 5000 rpm, but is still rather doggie off the line compared to its mid range performance. Probably I need either more rear gear or higher stall converter, and exhaust reconfiguration for better off line performance. All of which may lower fuel mileage which is presently around 18 mpg. Where I don’t race, but just putt-putt around town and go to car shows, I’ll leave things as they are for now.

I do run mid grade pump gas because before re-tuning, the car was so darn noisy I don’t think I could have heard pinging if it were there, and have just kept her on the diet. Now after the tuning she has much better manners, and is quieter.

The reason for the 390 is; it was there when I purchased the car as were the Clifford manifold, headers, and cam. Perhaps a large two-barrel, and a different cam would give better performance, I don’t know, I just worked with what I had.

You would probably not gain much performance over a properly executed Super six set-up if you went to the 390 4V without cam, head, tuning, and exhaust work.

Just my $0.02 worth...

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

I would have to dig up specs on motor builds, but both my slants run a Holley 390 with both being driven very regularly. My valiant is driven damned near every day (until the Indiana slush and salt hit the road) and my roadster which is driven on just about any given sunny day. Both motors are similar builds with mild street cams, little shaved off the head, one ha headers, one has clifford intake and the other has the offenhauser.

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Linder Tech.com
Bubba's Trailer Park

Where did you come up with shaving .030 off the head? I would go .090 or .100

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

Thanks for all the advice, guys. Sadly, the manifold is not drilled to let me mount the carburetor sideways. This is something I don't want to find out the hard way or apply half-fast engineering on. I have a Hurricane SL-6, so the fuel distribution should be better than the Offy.

The AED plate conversion arrived today. It includes a gasket, springs, and a float notched to clear the jets. The sun is shining and life is looking better.

I'll be installing the 390 on Hurricane and using a Bouchillon Performance kickdown cable. Now for the fun part of coming up with someway to mount the throttle and kickdown linkages at the engine. The Bouchillon kit has the bottom end of things very well covered. Since it's a universal Mopar kit, they would be hard pressed to cover every throttle linkage contingency.

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You can't fix stupid. - Ron White

I have mounted the carb sideways on the Hurricane manifold with a 1 inch spacer. I have not run it that way yet, However.
I used a square bore spacer.
Frank

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Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered